The invention relates to a mobile wet cleaning machine with a first tank for cleaning fluid, which is passed from said tank into the action region of at least one drivable cleaning tool for the floor surface to be cleaned, and with a second tank provided with a filter means, into which is introduced by means of a suction pipe the cleaning fluid taken up from the floor surface by a suction foot and from which cleaning fluid can be introduced into the first tank.
In one known wet cleaning machine of this type, which is marketed by the Tennant Company, Minneapolis, U.S.A. under the designation Tennant 527 SRS, the fluid comprising dirty water is sucked from the floor into the second tank, which comprises two portions. The first portion of the second tank receives the dirty water and includes a filter through which the water passes into the second portion. The filtered water is sucked by a pump from the second portion of the second tank to the brushes. An additional filter closes the inlet port to the pump line to prevent passage of any dirt particles which have entered the second portion into the pump.
This known wet cleaning machine, which has a relatively large construction, admittedly makes it possible to reuse the cleaning fluid and therefore provides a relatively long operating period before the entire cleaning fluid is used up and therefore refilling is necessary. However, it has a relatively complicated and costly construction, particularly due to the fact that it requires a pump, for which additional driving energy is required, for transporting fluid from the first portion of the second portion of tank to the second portion of the second tank.
It is also known to place a flexible bag with clean water in the dirty water tank of a small wet cleaning machine and from it the water for the cleaning process can be taken, so that the bag volume gradually decreases. Thus, there is a reduction in the degree of filling of the dirty water tank and the volume which is becoming free can be filled with dirty water.
Although this known wet cleaning machine has a compact construction and can also be constructed as a small unit, it suffers from the disadvantage that the volume of the cleaning fluid quantity to be used during a cycle is limited by the clean water bag volume, because the dirty water sucked up from the floor cannot be reused.